Type a aortic dissection after aortic wrapping performed 26 years ago: a case report

Abstract

Background

Aortic wrapping (AW) has been performed as a less invasive alternative to aortoplasty. However, AW can also cause long-term aortic complications. In this report, we present a rare case of a dissecting aortic aneurysm between the proximal side of the wrap and the sinotubular junction after AW.

Case presentation

A female patient had undergone urgent aortic valve replacement with a 19-mm mechanical valve to treat infective endocarditis and AW to treat an enlarged ascending aorta 26 years prior. At the age of 71 years, the patient was diagnosed with a dissecting aortic aneurysm between the proximal side of the wrap and the sinotubular junction. We performed graft replacement of the ascending aorta, including complete resection of the wrap. The patient was discharged on postoperative day 10, and there have been no cardiovascular events during her ongoing follow up.

Conclusions

AW in younger patients can lead to late aortic complications. Careful consideration should be paid when performing AW in young patients, and patients who have previously undergone AW require strict life-long follow-up.

Background

Aortic wrapping (AW) was first reported in 1956 and has been performed as a less invasive alternative to aortoplasty [1]. Even in acute type A aortic dissection, for which graft replacement is the gold standard, a recent study reported on the efficacy of AW [2]. However, AW can also cause long-term aortic complications [3]. Here, we report a rare case of a dissecting aortic aneurysm (DAA) between the proximal side of the wrap and the sinotubular junction (STJ) after AW.

Case presentation

A 71-year-old woman had undergone urgent aortic valve replacement (AVR) with a 19-mm mechanical valve to treat infective endocarditis 26 years prior. She also had undergone AW just distal to the STJ using PTFE felt because she had a bicuspid aortic valve and enlarged ascending aorta. An outpatient echocardiography revealed an elevated aortic valve pressure gradient (mean pressure gradient: 32.2 mmHg) caused by pannus formation and enlargement of the ascending aorta incidentally. Computed tomography (CT) revealed distal migration of the wrap and DAA, with a maximum minor-axis diameter of 57 mm between the proximal side of the wrap and the STJ (Fig. 1). We therefore scheduled re-AVR and graft replacement of the ascending aorta. An additional movie file shows the full surgical details (see Additional file 1). Following successful re-sternotomy without injury, cardiopulmonary bypass (CPB) was established via cannulation of the femoral artery and right atrium. The wrap had firmly adhered to the surrounding tissues. While the patient was cooled to 20 °C, careful resection was performed between the wrap and surrounding structures. Over 35 min of hypothermic circulatory arrest, the wrapped aorta (Fig. 2a) was completely resected, and distal anastomosis was performed between the 26-mm artificial vascular graft and the aortic hemiarch. On the distal side, felt strips that had been used to stop bleeding had eroded into the aorta (Fig. 2a). An intimal tear was observed between the proximal side of the wrap and the STJ. The ascending aorta, including the intimal tear, was resected. After the mechanical valve was removed, the pannus was dissected, and the annulus of the non-coronary cusp was reconstructed using bovine pericardium to repair damage from the previous surgery. Re-AVR was performed using a 19-mm bioprosthesis. Once proximal anastomosis was completed, the patient was successfully weaned from CPB. Postoperative CT revealed no aortic complications (Fig. 2b). The patient was discharged on postoperative day 10 and is currently undergoing follow-up as an outpatient; no cardiovascular events have so far been detected.

Fig. 1

Contrast-enhanced computed tomography showing the wrapped aorta. (a) and dissecting aortic aneurysm (DAA) (b). Three dimensional-volume rendering of the aorta showing DAA between the proximal side of the wrap (red arrow) and the sinotubular junction (yellow arrow) (c)

Fig. 2

(a) Morphological examination of the extracted wrapped aorta showing eroded internal felt strips (red arrow). (b) Three dimensional-volume rendering showing that the ascending aorta had been successfully replaced with the artificial vascular graft, without anastomotic complications

Discussion and conclusions

In this case, a late aortic complication occurred in a wrapped aorta; however, 26 years post-procedure, no dilation of the wrapped segment was observed, in contrast to the non-wrapped segment. Some reports of AW for a dilated ascending aorta with relatively good clinical results have been noted [4, 5]; moreover, this case does not report a poor outcome as no dilation of the wrapped segment has been observed for 26 years. We report a rare case of late aortic complications following AW, wherein localized DAA occurred between the proximal side of the wrap and the STJ. AW can have various biomechanical effects on the aorta. It may promote intimal hyperplasia and increase wall stress in nearby sections or cause structural and histological changes because the persistent pressure of the external prosthesis on the aorta induces vasa vasorum dysfunction and chronic inflammation [3]. In this case, biomechanical, structural, and histological changes caused by AW may have caused distal migration of the external prosthesis and tearing of the native aorta. The fact that her valve was bicuspid may also have affected the aorta. Few reports in the literature discuss reoperations after AW. Ehrich et al. performed a Bentall procedure with complete resection of a wrapped aorta to enlarge the sinus of Valsalva after AW [6]. When reoperations are needed after AW, the wrapped aorta should be removed as completely as possible to avoid late complications. However, complete resection can be difficult if the wrapped aorta tightly adheres to the surrounding tissues. Adhesion between the pulmonary artery and external prosthesis is often particularly strong. In our case, the wrapped aorta was peeled off from the pulmonary artery without injury because aortic pressure was decreased via cross-clamping and circulatory arrest. The peeling very close to the aorta, which was reinforced with the external prosthesis, may have prevented damage. However, careful consideration should be paid when performing AW in young patients because reoperations to treat distal late aortic complications are difficult. If any young patients undergo AW, strict life-long follow-up is required.